A conventional universal wrench is disclosed in U.S. Pat. No. 3,897,703 and includes a first connector and a second connector, wherein the first end of the first connector has a rectangular hole so as to be connected with the driving part of the socket wrench, and the second end of the first connector has a hexagonal hole. The first end of the second connector has a head with a hexagonal and curved outer surface. The head is accommodated in the hexagonal hole. The second end of the second connector has a hexagonal recess so as to be mounted to a bolt. The most universal wrench has rectangular driving part to be connected with a socket like the wrench disclosed in U.S. Pat. No. 4,188,801.
The connection between the first and second connectors in U.S. Pat. No. 3,897,703 uses the hexagonal recess accommodating the head so that the head can be pivoted. However, when the rectangular hole of the first connector is connected with a socket wrench, the rectangular driving part of the second is then connected with a socket, the socket wrench, the universal connector and the socket is located on a straight line which extends for a significant distance and is not convenient for operation in a limited space such as in an engine room. If the hexagonal recess of the second connector is directly mounted to a bolt, although the total length is shortened, only one fixed sized bolt can be operated and this cannot meet the requirements of the users.
The present invention intends to provide a wrench with is easily operated and improves the shortcomings of the conventional universal wrenches.